Blumenthal H T, Flanigan G D, Mayfield R
Department of Community Medicine, St Louis University School of Medicine, MO 63104.
J Natl Med Assoc. 1991 Dec;83(12):1065-72.
A sharply focused study is presented defining the demographic characteristics of the catchment area of a St Louis health center and determining the blood lead (PbB) levels in children from 1977 to 1989. The sources of lead exposure are examined, and the adequacy of erythroprotoporphyrin (EP) determinations are evaluated to identify children with toxic levels. Mean PbB levels and prevalence rates at higher ranges were not only substantially higher in the catchment area population than in white children, but also significantly higher than in black children nationally. Since 1980, mean PbB declined progressively in the catchment area children, but it was not until 1989 that the mean PbB had declined to the 1980 level in white children nationally. PbB parameters in the catchment area children were not only higher than in children in other St Louis neighborhoods, but also higher than in children living in towns adjacent to a lead smelting operation. The environmental sources of lead considered here do not appear to fully account for the higher PbB levels in the children in the catchment area. Nutritional factors also need to be considered. Furthermore, the EP lacks both sensitivity and specificity for identifying children with PbB levels greater than or equal to 25 micrograms/dL and greater than or equal to 15 micrograms/dL. While this study identifies a community that has experiences a high prevalence of lead toxicity in its children, it also suggests that nationwide and even citywide estimates of the prevalence of lead toxicity based on EP screening may be significantly lower than actual prevalences.
本文呈现了一项重点突出的研究，该研究界定了圣路易斯一家健康中心集水区的人口特征，并测定了1977年至1989年儿童的血铅（PbB）水平。研究考察了铅暴露的来源，并评估了红细胞原卟啉（EP）测定的充分性，以识别血铅水平达到中毒程度的儿童。集水区人群的平均血铅水平及较高范围内的患病率不仅显著高于白人儿童，而且也明显高于全国黑人儿童。自1980年以来，集水区儿童的平均血铅水平逐渐下降，但直到1989年，其平均血铅水平才降至全国白人儿童1980年的水平。集水区儿童的血铅参数不仅高于圣路易斯其他社区的儿童，而且也高于居住在铅冶炼厂附近城镇的儿童。本文所考虑的铅环境来源似乎并不能完全解释集水区儿童较高的血铅水平。营养因素也需要考虑。此外，对于识别血铅水平大于或等于25微克/分升以及大于或等于15微克/分升的儿童，EP缺乏敏感性和特异性。虽然本研究确定了一个儿童铅中毒患病率较高的社区，但它也表明，基于EP筛查对全国乃至全市铅中毒患病率的估计可能显著低于实际患病率。
